摘要:
本文根据热电子发射的统计理论,运用无穷大平板二极管中考虑电子纵向热速度效应的电位状态与普通电子枪中阴极前面的电位状态相等效的处理方法,编写了电子枪的计算机程序,得到了计算的电子枪发射电流值与实测的电流值相一致的结果,文中还通过计算分析指出,在计算电子束管电子枪的发射电流时,必须考虑电子的纵向热速度效应,其计算的电流值比3/2次方定律的电流值大,且更接近实测结果;微波管强流电子枪中,电子纵向热速度效应在低工作电压下比在高工作电压下影响大些,但总的来说,比在电子束管中的影响小得多;电子纵向热速度效应对发射电流的影响随阴极的发射电流密度与阴极发射本领差别的增大而增加,但当这一差别大于一定值后,这种影响的大小趋于恒值。
Abstract:
A computer program for calculating emission current in an electron gun has been worked out, and good agreement between calculations and experiments has been achieved. The computation model is based on the statistical theory of thermal electron emission, and the potential distribution in front of the cathode is equivalent to that o f an infinite planar diode in which the effect of the longitudinal thermal velocity of electron (ELTVE) is included.It is shown by the computation:1. In the case of CRT, the ELTVE must be taken into account. The calculated currents are greater than that estimated by the 3/2 power law and are closer experimental results than in the latter case. 2. In high density gun, the ELTVE is noticeable when it works at low voltage, but on the whole it is much smaller than in a CRT gun. 3. The ELTVE becomes significant as the difference between the operating current density and the cathode loading limit increases, and the effect remains unchanged when thedifference is beyond a certain value.
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